proxddp → core Relation

File in include/aligator/solvers/proxddp	Includes file in include/aligator/core
merit-function.hpp	traj-opt-problem.hpp
results.hpp	results-base.hpp
solver-proxddp.hpp	callback-base.hpp
solver-proxddp.hpp	enums.hpp
solver-proxddp.hpp	filter.hpp
solver-proxddp.hpp	linesearch.hpp
workspace.hpp	workspace-base.hpp